This invention relates to an improved optical imaging head for use with optical imaging apparatus.
Optical imaging heads are widely used in duplicating, copying and master making machines. An optical imaging head typically includes a plurality of imaging devices having an associated light source and lens system configured to allow light rays representing a reproduced image to be directed onto a focal plane.
The optical imaging head is part of an overall optical imaging apparatus which provides reproduction, transmission and manipulation of an original image such as text material, graphic material and combination original images. The optical imaging head may be used with copying machines, typesetters, plotters, non-impact printers, plate makers, facsimile machines, and the like. Such machines typically include digital electronics which allow the original image to be translated into a digital signal, transmitted and reproduced by the imaging devices of the optical imaging head.
Over the years, a variety of optical print heads have been developed. One such print head which utilizes imaging devices which angularly impinge on a focal plane is illustrated in U.S. Pat. No. 4,376,282 to Kotani et al. However, such angular impingement of light rays forming the reproduced image results in increased character deformation and increased separation of alternate segments of the reproduced image. In addition, in such an angular optical print head, character deformation and separation of alternate reproduced image segments increases as the distance between the imaging devices and the focal plane is altered.
Electronic cameras including segmented reflecting structures also are known in the art. One such device is illustrated in U.S. Pat. No. 3,779,146 to Tranker. The segmented reflecting structure disclosed by Tranker directs a portion of the light rays passing through the camera lens toward a view finder and the remaining light rays to a light meter device. This electronic camera device does not utilize a segmented reflecting structure to direct a highly resolved reproduced image toward a focal plane in an electronic imaging device and does not address any of the problems encountered therewith.
In view of the short comings of devices previously known, there is a definite need for a new and improved optical imaging head providing perpendicular impingement of the light rays of the reproduced image onto the focal plane. In addition, it is desirable to provide an optical imaging head which reduces the deformation and/or distortion of each reproduced character; which reduces separation of alternate reproduced image segments, thereby producing an improved optically reproduced image having superior resolution and coherency; and in which the amount of character deformation and/or distortion, and the amount of separation of alternate reproduced image segments are not dependent on the distance between the imaging devices and the focal plane.
It is desirable to provide an optical imaging head which is simple in construction, efficient in operation and can be retrofitted to existing copying, duplicating, plate making, facsimile and similar machines.